Coiling apparatus



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Sept. 6, 1960 A. s. WALLIN COILING APPARATUS Filed neo. 23, 1954 4 VYsheets-sheet 1 Ine/@fam A. s. WALLIN coILING APPARATUS Sept. 6, 1960 4 Sheets-Sheet 2 Filed Dec. 23, i954 @essaye .5o urce IZ e/ezz i??? CZIZU? 5 Ja fare Sept. 6,1960 A. s. wALLlN 2,951,657

corLING APPARATUS Filed Dec. 23. 1954 4 sheets-sheem s Sept. 6, 1960 A. s. WALLIN conm@ APPARATUS 4 Sheets-Sheet 4 Filed Dec* 23, 1954 b www United States Patent O COILING APPARATUS Arthur S. Wallin, Chicago, Ill., assignor to Hydrometals, Inc., a corporation of Illinois Filed Dec. 23, 1954, Ser. No. 477,352

11 Claims. (Cl. 242-781) The present invention relates in general to apparatus for coiling strips or sheets of materials such as heavy gauge metal and, in particular, to metal coilers of the type which employ rotatable mandrels.

The general aim of the invention `is to make the operation of metal coilers substantially automatic in their function of successively coiling metal strips, thereby minimizing the attention required of an operator and aifording faster and more reliable perfomance.

Concurrent with that aim, other objects of the invention are to provide a coiler which is especially useful in coiling relatively thick and heavy metal strips; which causes successive metal strips to be automatically fed "to and clamped in a mandrel; and which has the mandrel automatically repositioned to receive the next strip after a completed coil has been ejected.

Still other objects are the provision of an improved and simplified self-locking mandrel, novel guide means for leading metal strips into threaded engagement with a mandrel, which means require no airmative positioning by an operator but which in no way interferes with the ceiling action; and improved control means for relocating the mandrel in its threading position.

Additional objects and advantages will become apparent as the following description proceeds, taken in conjunction with the accompanying drawings, in which:

Figs. l, 2 and 3 are side elevational, rear elevational and plan views of a heavy metal coiler embodying the features of the present invention;

Figs. 4 and 5 are enlarged fragmentary end views of the mandrel employed in the metal coiler and shown in its unlocked and locked conditions, respectively; and

Fig. 6 is a schematic diagram of an electric control circuit for the metal coiler.

`Although the invention has been shown and described in` some detail with reference to a particular embodiment thereof, there 4is no intention that it thus be limited to such detail. On the contrary, it is intended here to cover all modications, alternative constructions and `equivalents falling within the spirit and scope of the invention as defined by the appended claims.

' Referring now to the drawings, initially to Figs. l, 2

and 3, the invention has been illustrated as embodied in a heavy metal coiler 10 which comprises a supporting frame 11 mounting 'a rotatable mandrel 12 which is adapted to receive and coil metal strips 14 supplied successively along an underlying feed conveyor 15 from a rolling mill or other source (not shown). The metal strips 14 are fed into thereaded engagement with the `mandrel 12 by a guide chute 16, the operation being such that each strip is coiled on'the mandrel and then ejected, after which the ooiler is automatically recondip tioned `to receive `a succeeding strip in rapid sequence. As` shown, the mandrel 12 is mounted on the output .shaft18 of -a speed-reducing gear box 19 supported in ,the frame; 11. The input `shaft 20l ofthe gear box 19 is `driven by a series of V-belts .211mm ,a 'power sourcey such as electric motor M. 'Ihe mandrel 12 may be brought to a quick stop by means of an electric brake 22 supported in the frame and operative on the gear box input shaft 20. This brake is of the type that is normally applied, and released when electrically energized.

Completed coils are ejected from the mandrel 12 by a pusher plate 24 axially reciprocable along the mandrel 12 and formed with a centr-al opening 24a through which the mandrel projects. Reciprocating movement of the pusher plate 24, which is mounted on a pair of spaced rods 25 which are slidably carried in the upper portion of the frame 11 and connected to a crosspiece 26, is produced by a piston 28 slidable in a cylinder 29 of a double-acting hydraulic or pneumatic ram 30. The `supply and exhaust of fluid to and from the ram 30 is controlled by a pair of solenoid valves 31, 32 actuated by coils 31a, 32a (Fig. 6) and connected to the cylinder `on respective sides of the piston 2S. The valve 3-2 is normally open and the valve 31 normally closed so that the piston 28 is held in the retracted position illustrated by Fig. 3, that is, with pressure fluid supplied through the valve 32, and the rear end of the cylinder 29 vented through the valve 31.

Upon energization of solenoids for these valves, the front side of the piston 28 is vented and its rear side supplied with pressure fluid to advance the pusher plate 24 along the mandrel 12. This 4action ejects a compreted coil from the mandrel onto a cross-over conveyor 34 which carries the coil to a delivery location or to other metal working apparatus.

`In accordance with the invention, the mandrel 12, `guide chute 16, and controls for the drive motor M and brake 22 are cooperatively arranged to make coiling of successive strips 14 substantially automatic.

For this purpose, the mandrel is constructed with novel means for automatically locking the leading edge of the strips 14 as the latter 4are thereaded therein by the guide chute 16. As here shown, the mandrel 12 is made as a cylindrical drum 36 closed by end plates 38 which carry collars 59 telescoped over and locked to the gear box output shaft 1S by means such as keys 40 and bolts 41, `The drum 36 is formed with an -axial slot 42 extending inwardly along a chord of the drums cross section as best illustrated by Figs. 4 and 5. With the mandrel in the angular position illustrated, the lower defining side'o-f the slot 42 has a relieved portion at 44 near the slot mouth, and the upper defining side of the slot 42 is formed with a recessed portion 4S located inwardly from the slot mouth. A locking plate 46 is pivotally overbalanced in the slot l42 so that it normal-ly falls to the vopen position illustrated by Fig. 4 in which its outer edge rests on the relieved portion 44, its `inner edge correspondingly entering the recessed portion 45. The plate 46 may be pivoted, for example, on a rod 4S extending axially of the drum and carried by brackets 49 bolted to the end plates 3S.

With the mandrel in the threading position illustrated by Fig. 4 and with the plate 46 rocked to the open position due to its overbalanced weight, the leading edge of a metal strip 14 travelling upwardly at an angle corresponding to that of the plate 46 is threaded into the slot 42. As the strip 14 pushes its way into the inner part of the slot 42, it bears on the inner edge of the plate 46 and rocks the latter to the clamping position illustrated by Fig. 5. The strip is thus clamped between the outer edge of the plate and the upper side of the slot 42 and cannot pull free as the mandrel begins to rotate. With `such rotation, the strip 14 is thus given a relatively .sharp `bend at its point ofV entry `into the slot 42 and is .securely held by the Aplate 46 as the coiling operation proceeds.. It `will be noted that the pivotal movement Patented sept. 6, 1960- of the rocking plate 46 is responsive to and caused by `contact of the strip 14 therewith and requires no separate actuation on the part of an attendant or operator.

For threading the leading edge of a strip 14 approaching valong the underlying'co'nveyor 15 -into the mandrel slot,42, the guide chute 16 is hinged to the conveyor Yat lits lower or entrance end 16a. Preferably this guide 'chute is open along one side to permit ejection of a coil lhaving a'tail, and is tapered toward its upper or exit end 16h to' confine the leading edge of the stripV as it approaches the mandrel slot 42. Entry of the strip into the slot 42 when the mandrel 12 is rotationally indexed as illustrated in Figs. 1 and 4 is assured by the provision of means for biasing the chute 16 to an upwardly inclined position such that its upper end is adjacent the mouth of the slot and substantially parallel to the open plate 46. Such biasing means in the illustrated embodiment take the form of a weight 50 connected by a cable V51 running over a pulley 52 and mounted at the exit end .16b of the chute. .The weight 50 normally drops to rest on a limiting platform 54 so that the chute is held in the inclined position illustrated by dashed lines in Fig. l.

With the guide chute 16 so biased to an inclined posintion, the leading edge of a strip 14 travelling 'along the conveyor 1'5 is directed upwardly and into the slot 42 of the mandrel 12. Subsequent rotation of the mandrel not only causes automatic locking of the strip 14 in the slot 42 but also causes the strip 14 to rock the chute 16 downwardly into a Vtangential position with respect to the mandrel against the biasing force of the weight 50 (solid lines, Fig. 1). Accordingly, no airrnative action `on the part of an operator is necessary to position the chute in its threading position or into its lower tangential position.

For the automatic control of the motor M and the brake '22, limit switches are employed and connected in acontrol circuit which provides the automatic action to be described. As illustrated in Fig. l, a first limit switch LS1 is located on the conveyor 15 (Fig. l) and is pro Vvided with an actuating finger 60 which is adapted to be depressed by the strip 14. The switch LS1 is employed to initiate rotation of the mandrel. For stopping the mandrel so as to leave a tail extending from the com- Y pleted coil, a second limit switch LS2 having an actuating iinger 61 is likewise disposed on the conveyor 15. This switch is moved to closed position by the strip `14 and is released whenever the trailing edge of the strip moves clear of the finger 61.

A third normally closed limit switch LS3 (Fig. 3)

Vis mounted on the frame 11 with its actuating iinger 62 'disposed in the path of a collar y64 carried by one of the guide rods 25. The relative locations of the nger 62 and collar 64 are such that the switch LS3 is opened when the pusher plate 24 is fully extended by the ram 30 in ejecting a completed coil onto the cross over conveyor 34. For the automatic reindexing control of the mandrel, a fourth limitswitch LS4, normally open, is similarly mounted on the frame 11 in a position to have its actuating finger 65 momentarily tripped, and its contacts momentarily closed, by the collar 64 as the pusher plate 24 is returned to its retracted position.

A fth limit switch LS5 (Fig. l) is also carried by the frame 11 and cooperatively disposed with respect to a cam 66 fast on the mandrel-supporting shaft `18. A

` raised portion 66a on the cam 66, which is adapted to trip the finger 68 of the switch LSS as the mandrel passes through a predetermined rotational position.

- With the locations of these limit switches in mind, the control circuit and its operation may now be understood with reference to Fig. 6. i

ln accordanceV with the invention, the control circuit forthe motor M is adapted to automatically re-index the mandrel 12 to the threading position illustrated by Figs. 1 jand 4 in response to the ejection of `a completed coil. Thus, shortlyafter one coil'has been Vremoved from .the

Yt-he coils of respective control relays R1 and R2.

ergize the motorv M so that coiling begins.

4 mandrel the latter is ready to receive the next strip 14 without any airmative action being necessary on the part of an operator. In the accomplishment of this operation, the controls include means for momentarily energizing the drive motor M `and releasing the brake 22 when a completed coil has been ejected, together with means for applying the brake 22 and momentarily plugging the motor M as it passes through a predetermined rotational positionrso that it Vis stopped in exactly the threading position illustrated. Time delay means or relays susceptible of timing Yadjustment are employed so that exact positioning maybe obtained with little trouble. Referring now to Fig. 6, the exemplary control circuit for the motor M and the coil 22a for the brake 22 includes forward and reverse contactors having coilsV F and R respectively associated with contacts F1-3 and R1-3. These contacts, when closed, forwardly and reversely energize the three-phase induction type motor M from a suitable three-phase voltage source. The coils R 4and F are connected in a control circuit supplied with a suitable control voltage to the lines L1, L2 through a transformer T. Y Y l Thecoil of a first time delay relay TD1 is connected in series lacross the lines L1, L2 with the normally open cont-acts of the two limit switches LS1 and LS2. The relay TD1 has two normally open contacts TDla and 'IDlb which are arranged in series across the lines L1, L2 with The latter relays Ihave normally open contacts Rla and R2 disposed in series across the control voltage source with the contactor coil F and the brake coil 22a, respectively. Therefore, when the time delay relay TD1 is picked up, the relay 'R1 is energized to close its contacts R111, thereby energizing the coil F and causing the motor M to rotate in. a rforward direction, i.e., counterclockwise as viewed in Figs. l and 4. Correspondingly, pick up of relay TD1 energizes the relay R2 so that the contacts R2a energize the brake coil 22a and release the brake 22.

The initial phase of operation resulting from this arrangement may be best summarized at this point. As the leading edge of la str-ip 14 advances down the con- `veyor ,15, it tirst closes limit switch LS2 and then closes 'limit switch LS1 thereby energizing the relay TD1. The

delay period of the latter is set to allow the leading edge vof the lstrip 14` to be fully inserted into the mandrel slot 42 'before its contacts TDla, TDlb close. As soon as .the strip is inserted into the slot 42, however, the latter contacts close -to release the brake 22 and forwardly en- When the trailing edge ofthe strip 14 releases the limit switch LS2, the relay TD1 is deenergized and immediately opens its contacts TDla, TDlb. This stops themotor and deenergizes the brake coil 22 so that the brake brings the mandrel to a quick stop, thus leaving a tail extending from the completed coil along the conveyor 15.

Wit-h the coil thus completed andthe mandrel stopped, the operator then depresses, a single normally open control switch S Which is connected in series with the coil of a third control relay R3 across the supply lines L1, L2. As the relay contacts R3a close, the coil R3 is sealed in through the normally closed contacts of the limit switch LS3, while normally open contacts R3b of this relay energize theVv coils 31a and 32a of the respective solenoid valves 31V and 32. Accordingly, the ram 30 is actuated `to shift the pusher plate 24 axially along the mandrel 12,

thereby causing the completed coil to be deposited on the cross-over conveyor 34. As soon as the pusher plate reaches theend of its travel, the collar 64 ,(Fig. 3) trips the limit switch LS3 to open thel contacts'of the-latter, 'thereby unsealing the relay R3 and causing its contacts to theirzoriginal positionsfl As the pusher plate reachesits retracted position, the collar `64 (Fig. 3) momentarily trips the limit switch LS4 to close the contacts of the latter. These contacts are connected in series across the supply lines L1, L2 with the coil of 'a fourth control relay R4 having four normally open contacts R4a-d (Fig. 6). As the relay R4 is picked up, its contacts R4a complete a seal-in circuit through normally closed contacts "ID-la of a time delay relay to be described. Closure of the contacts R4b energizes the coil of a second time delay relay TD2; closure of the contacts R4c prepares further circuit components for energization, while closure of the contacts R4d result in energization of the control relay R1 through normally closed contacts TDZa of the second time delay relay, and at the same time causes energization of the control relay R2 through normally closed contacts R6a of a con trol relay to be described below. As a result, the contacts Rla close and the contacts R2a open to respectively energize the motor contactor coil F and the brake coil 22a, thereby causing forward rotation of the motor M and release of the brake 22.

The motor M is thus momentarily energized in a forward direction until the time delay relay TD2 times out and its contacts TD2a open. With this, the relay R1 and contactor F drop out to deenergize the motor M, although the relay R2 remains energized through the contacts R4d so that the brake coil 22a remains energized and the brake 22 remains released. The relatively short period of forward ener-gization for the motor M rotates the mandrel until the cam portion 66a (Pig. 1) trips the normally open fifth limit switch LSS. When this occurs, the coil of a fifth control relay R5 is energized through the already closed contacts R4c, limit switch LSS, and through the normally closed contacts TD3a of a third time delay relay TDS. As the relay R5 picks up, its normally open contacts RSa close to create a `seal-in circuit from the line L1 through the contacts R4c to the line L2. Coin- `cidentally, contacts R5b close to connect the coil of the time delay relay TDS directly across the lines L1, L2. Then, the mandrel shaft coasts for la time interval determined Iby the setting of the time delay relay TDS. This interval is very short so that the limit switch LSS remains closed under the inuence of the cam portion 66a during the TDS relay timing period. When the latter relay picks up, its cont-acts TD3a drop out the relay R5, and its contacts TDSIJ clo-se to energize the coil of a sixth control relay R6 through the already closed contacts R4c and LSS.

Closure of the contacts TD3b also energizes the coil of `a seventh control relay R7 through normally closed vcontacts TD4b ofthe fourth time delay relay TD4.

The results are as follows: The relay R6 is picked up and sealed in through its normally open contacts R6b and the already closed contacts R4c. The contacts R6c close to directly connect the coil of the relay TD4 across the lines L1, L2. And the normally closed contacts R6a open to deenergize relay R2, thereby deenergizing the brake coil 22a and Iapplying braking force to the gear reducer input shaft. As a further result, energization of .the relay R7 closes its normally open contacts R7a to energize the contactor R so that the motor M is reversely energized or plugged The brake 22 is applied and the motor M plugged for a short interval to bring it to an abrupt stop in the threading position, this period being determined by the setting of the time delay relay TD4. When the latter times out, its contacts TD4!) open thereby dropping out the relay R7, the contactor R, and leaving the motor M deenergized. Also at this time, the contacts TD4a open to unseal the circuit for the coil of relay R4, the result being that the contacts R4a-d open dropping out all other reposition for threading of the next met-al strip through the guide chute 16 and into the slot 42.

It will be readily apparent to those skilled in the art that adjustments may be made to set the delay intervals of the various time delay relays TD1-TD4 so that the mandrel will always stop in proper threading position, Reliability is assured since the reindexing is accomplished by (a) momentarily energizing the motor (for a period determined by relay TD2) to rotate in a forward direction, (b) letting it coast for a predetermined period of time (determined by relay TDS) and through a predetermined angle from the position in which the limit switch LSS is -tripped by the cam 66 (c), and plugging the motor and applying the brake 22 for a predetermined time interval determined by the setting of the time delay relay TD4 so that the mandrel stops in the desired position.

While the operation of the entire coiler 10 will be apparent from the foregoing description of its construcv tion and its control circuit, Ia brief summary of the advantageous functions may be helpful. As a first metal strip 14 rides along the conveyor 15, its leading edge is directed upwardly through the guide chute 16 which is biased to an inclined position -by the weight S0. When the leading edge of the strip 14 becomes inserted in the mandrel slot 42, the time delay relay TD1, originally energized by the limit switch LS1, starts the drive motor M to commence the coiling automatically. As the coiling begins, the guide chute 16 is rocked downwardly (clockwise in Fig. 1) by the strip itself so that it assumes a position tangential tothe mandrel and in. no way interferes with the coiling operation. The locking plate 46 is rocked by the strip itself to the clamping position illustrated by Fig. 5, thereby holding the strip firmly.

When the trailing edge of the strip 14 releases the limit switch LS1, the relay TD1 drops out to deenergize the motor M and apply the brake 22, thus stopping the mandrel with a tail on the coil. Next, the completed coil is ejected from the mandrel in response to the operator momentarily closing the push button switch S which energizes the solenoid valves 31, 32. When the ejecting stroke of the pusher plate 24 is complete, the limit switch LS3 opens to deenergize the solenoid valves and to retract the pusher plate. As the retraction is completed, the limit switch L34 is closed to begin the time controlled sequence noted above which results in (a) momentary energization of the motor for a predetermined time interval so that the mandrel reaches a certain rotational speed, (b) coasting of the mandrel for a predetermined time from the instant it passes through the rotational position in which the limit switch LSS is tripped by the cam 6.6, and (c) plugging of the motor to stop the mandrel in position to be threaded by the next strip 14 approaching over the conveyor 15. The only conscious action required of an operator is to press the push button switch S each time that a coil has been completely formed on the mandrel.

I claim:

1. For use in coiling apparatus, a conveyor along which metal strips are successively supplied, and a metal coiler, said coiler comprising, in combination, a rotatable man.- drel disposed above the conveyor, a motor for driving said mandrel, means on the mandrel for locking the leading edge of a met-al strip upon contact therewith, means including a pivoted guide normally biased to lead the metal strip from the underlying conveyor upwardly to said locking means when said mandrel is in a predetermined rotational position, said guide being rocked to a position tangential `of said mandrel as an incident to coiling of the strip, means for ejecting a completed coil from said mandrel, and means for controlling said motor in response to the ejection of a completed. coil for automatically re-indexing said mandrel to said predetermined rotational position.

2. A `heavy metal coiler comprising, in combination,

`a cylindrical mandrel having a slot extending inwardly ypartially along a chord thereof, a pivoted element in said slot Lfor clamping fa `metal strip .l as an 4incidenttouthe 7 threading of the latter into the slot, a'pivoted guide chute yieldably biased to a position for threading the strip into the slot when the mandrel is in a4 predetermined rotational position, said chute being rocked by the metal strip to a position tangential to the mandrel as coiling begins, a push-off member adjacent to and movable axially along said mandrel to eject a completed coil, a motor for driving-said mandrel, and control means operative on said motor and responsive to the ejection of a completed coil for automatically indexing said mandrel with the slot in position for rethreading.

3. A heavy metal coiler comprising, in combination, a motor, a cylindrical mandrel driven by said motor and having an axial slot therein extending substantially along a chord thereof, the lower side of said slot having a relievedrportion near the slot mouth and the upper side having a recessed portion inwardly from the slot mouth, a locking plate pivoted in said slot and overbalanced to an open position with its outer and inner edges bearing respectively against said relieved and recessed portions, said plate being rocked to clamp the leading edge of a metal strip as an incident to entry of the latter into said slot, a tapered guide chute pivotally mounted beneath said mandrel, means biasing said chute to an upwardly inclined angle to thread the metal strip into said slot when said mandrel is indexed to a predetermined rotational position, said chute being rocked to a position' tangential of the mandrel as an incident to coiling of the strip, a pusher plate axially reciprocable along said mandrel to eject a completed coil, a iirst limit switch actuated upon return of the pusher plate, means responsive to the actuation of Said rst limit switch toforwardly energize said motor, rst time delay means operatively connected to deenergize said motor after a predetermined period of forward energization, a cam rotatable with said mandrel, a second limit switch actuated by said cam as said mandrel passes through a preselected rotational position, means responsive to the actuation of said second limit switch for reversely energizing said motor, and time delay means operatively connected to deenergize said motor after a predetermined interval of reverse energization to thus reindex said mandrel to said predetermined position to receive the next metal strip. 4. For use in a metal coiler, a self-locking mandrel comprising in combination, a cylindrical drum having a slotV dened in its surface and extending inwardly along a chord of the drum cross section, said drum having a recess spaced from the surface of the latter and communicating with said `slot so as to receive the end of a metal strip inserted in said slot, an overbalanced locking member pivotally disposed in said slot and rockable about an axis parallel ,to the axis of said drum and in a direction to clamp sa-id metal strip adjacent its end against the edge of the said slot at a point in said slot between said recess and the surface of the drum as an incident to entry of the metal strip therein, said drum being rotatable so as to coil the metal strip around the drum in the direction leading laway from the slot from the edge at the intersection between the said side of the slot and the drum surface. A5. In a metal coiler, a self-locking mandrel comprising, in combination, a cylindrical drum having a slot formed therein and extending inwardly substantially along a chord of the drum cross section, the radially inwardly lying side of said Vslot having a relieved portion at the slot mouth `:and the radially outwardly lying side having a recessed portion in the medial portion of the slo-t and spaced from :the surface of the dnurn, a locking plate in said slot pivoted about an axis parallel to the axis of the drum and rockable fbetween (a) an open position in 'which its' outer and inner edges bear respectively against said relieved and recessed `portions,V andY (b) a'closed position in which 'the outer ",edge of the plate bears against the side of said `slo`t at a lpointiopposite the relievedtportion and adjacent the sur- 'frfacezof the' drum, whereby (a, metal strip is Vclamped Ybetween said plate and said latter side of theslot as an'incident to entry of the strip into said slot. i

'16. For use in coiling apparatus, a self-locking mandrel comprising, in combination, a cylindrical drum having a slot formed therein and extending inwardly substantially along a Achord of the drum cross section offset from the center thereof, the radially inwardly lying side of said slot having a relieved portion at the slot mouth, and the radially outwardly lying side of the slot having a recessed portion located inwardly of the slot mouth, a locking plate disposed in said slot, means pivotally mounting said plate to rock about an axis parallel to the drum axis, said plate being overbalanced so that it normally swings to an open position with'its outer and inner edges bearing against said relieved and recessed portions, respectively, the entry of a strip into said slot thereby rocking said platein a direction to automatically clamp the strip between the outer edge of the plate and the radially outwardly lying side of the slot at a point opposite said relieved portion adjacent the surface of the drum, said drum being rotatable so as to coil the strip around the drum in the direction leading away from the slot from the edge at the intersection between the radially outwardly lying side of the slot andthe drum surface.

7. For use in coiling apparatus the combination cornprising, a mandrel, `a feed conveyor underlying said mandrel, means for receiving the leadingedge of a strip travelling along said underlying feed conveyor, means for directing the strip into the mandrel, strip-receiving means comprising a chute hinged to the conveyor, and means biasing said chute into alinement with the mandrel strip-receiving means, coiling of the strip thus causing said chute to rock against the iniluence Vof said biasing means to a position tangential of the mandrel.

8. In a heavy metal coiler having a slotted mandrel, a conveyor underlying said mandrel, said mandrel being indexable to a position in which the slot is upwardly inclined to receive the leading edge of a metal strip travelling along said underlying conveyor, guide means comprising, in combination, a hollow tapered chute hinged at its larger entrance end to the conveyor, and means for yieldably biasing said chute to an upwardly inclined angle such that its smaller discharge end is opposite'and alined with the mandrel slot to direct the leading edge of a metal strip from the conveyor into the slot, coiling of the strip thus rocking said chute downwardly'to a position tangential with the lower side of said mandrel.

9. For use in metal coiling apparatus having a mandrel, a conveyor'underlying the mandrel, said mandrel being slotted along a chord thereof and indexable to a position in which the slot is upwardly inclined to receive the leading edge of'a metal strip travelling down said underlying conveyor, guide means for directing the strip into the mandrel slot, said guide means comprising, in combination, a taperedV guide chute open on one side and having its larger entrance end hinged to the conveyor, and means including a weight and pulley'for biasing said chute to an upwardly inclined 'angle with its smaller discharge end opposite the mand-rel slot, whereby coiling of the strip on the mandrel proceeds without interference from the chute, the latter being rocked downwardly by the strip to a position tangential with the underside of the mandrel.V

l0. In a metal coiler having a mandrel, a motor for driving the same, and means for ejecting complete coils from the mandrel, control means for automatically indexing the mandrel to threading position comprising; in combination, means for forwardly energizing said motor for a predetermined period in response to the ejection of a completed coil, a limit switch, a cam rotatable with the mandrel and operative to close said switch as the `mandrel passes through a' predetermined angular position, first time delay means l,responsive to actuation of `said limit switch for reversely energizing 'said motor after a predetermined period from the instant said limit switch is closed, and means to deenergize said motor after a predetermined period of reverse energization to thereby stop the mandrel in threading position.

11. Ina metal coiler having la slotted mandrel, a motor for driving the mandrel, a brake for the mandrel, and a Y pusher plate movable axially of the mandrel for ejecting completed coils, control means for automatically indexing said mandrel to be yrethreaded upon the discharge of a completed coil comprising, in combination, a rst limit switch adapted to be tripped upon return of the plate from its ejection stroke, means responsive to tripping of said 10 limit `switch for forwardly energizing the motor and releasing the brake, a rst time delay relay energized by said first limit switch and operative to deenergize the motor latter =a predetermined period, a cam rotatable with the mandrel, a second limit switch tripped by said cam as the mandrel passes through a predetermined rotational position, a second time delay relay energized in response to tripping of said second limit switch, means responsive to the delayed pick-up of said second time delay relay for 10 reversely energizing the motor, and a third time delay relay energized in response to pick-up of said second time delay relay and operative after la predetermined period to deenergize the motor and apply the brake to thereby stop the mandrel in threading position.

References Cited in the le of this patent UNITED STATES PATENTS 

